I see you live in Henderson NV - I moved here from Phx AZ: The hot here is nothing like the hot there. Yes, it's a dry heat there (Angioplasty - TX is not a dry heat honey and 108 would be cooler than where she is from), but when it's 120 degrees who cares how dry it is, it's way too frickin hot! So yes, it gets hot but it's nothing you can't deal with coming from Henderson, as a matter of fact for the first couple years it'll feel downright cool!.
I grew up in NoCal, lived in Phx for 10 years, and have relatives in SoCal - I love Dallas. It's huge, there's something to do for everyone, if you are complaining there's not then you are either not looking or being picky. It's extremely welcoming. I have felt more welcomed and included here by neighbors, co-workers, strangers at the store than anywhere else I've lived.
There is PLENTY to do outdoors here, and a lot less people competing for the outdoor resources than in SoCal, lol. We spend much more time outdoors here than we did in AZ. We ride horses, hubby and the kids hunt, we hike, run, bike, play soccer, swim etc etc etc. Many neighborhoods have neighborhood pools that don't require membership or waiting lists. We swam in ours daily last summer and no one got sick! There are also many more waterparks than just Hurricane Harbor - we've been here 6 years done multiple waterparks every year and haven't even been to Hurricane Harbor yet!
Dallas is a huge metroplex, like LA. You need to know which area you are interested in to get the right feedback. Do you want to live in downtown? East Dallas (greener, more lush)? Fort Worth (more prairie)? North? Etc Etc Etc. It's like asking someone from Burbank to tell you about El Centro, or Thousand Oaks, or Costa Mesa - they are different areas with different things to offer.
Every city has it's pros & cons. You can find someone in every town that hates it. Figure out where you want to go, then do some research and take everything with a grain of salt.